1. Field of the Invention
The present invention relates to wooden dowels that have a self-contained, integral coating of a water soluble glue on the external surface of the dowels. In particular, the present invention relates to a process and apparatus for coating such dowels with the water soluble glue.
2. State of the Art
In production of cabinets, furniture and other similar items from wood, adjoining pieces of wood are held securely together with wooden dowels. Dowel receiving cavities are formed in each of the respective pieces of wood that are to be held together. When the pieces of wood are assembled, liquid glue is injected into the dowel receiving cavities. To be sure that sufficient glue is used in each cavity an excess of glue is used in each cavity. When the dowel is inserted, glue is expelled from the cavity. The expelled glue creates a messy situation with glue getting on everything around the pieces of wood as well as on to the pieces of wood themselves. Cleaning of the glue is a major labor item and adds to the cost of the wood items being produced. However, manufacturers have found that the use of excess amounts of glue is essential. When the excess of glue is cut back, many of the dowel connections for one reason or another become weak due to insufficient or improper distribution of glue around the dowels in the cavities.
In my copending U.S. patent application Ser. No. 07/766,590 filed 9/21/91, now U.S. Pat. No. 5,259,686 there is disclosed wooden dowels having an external coating of a water soluble glue. These dowels have been found to be preferable to ordinary dowels in many applications. Instead of introducing an excess of messy glue into the cavities of wood pieces that are to be held together by the dowels, manufacturers introduce water into the cavities. The dowels that are precoated with a water soluble glue are then inserted into the cavities expelling excess water instead of excess glue from the cavities.
The precoated dowels of my previous application were made by a labor intensive, manual operation. To be commercially viable, a less labor intensive, mechanized method and apparatus had to be developed.